Improvement in steam-pressure gauges



Patented June 25,1872.

J. KAYSER. Improvement in Steam-Pressure Gauges. vN0.'l28,401.

Inrrnn gramas JOSEPH KAYSEB, OF NEW YORK, N. Y.

IMPROVEMENT Ir STEAMHFRESSRE GAUGE-2S.

Specification forming part of Letters Patent No. 128,401, dated June 25,1872,

t tion thereof, which will enable those skilled in the art to make anduse the same, reference being had to the accompanying drawing formingpart of this specication, in which draw- Figure l represents a face viewof my gauge, a portion of its dial-plate being broken away so as toexpose the working parts. Fig. 2 is a transverse section of the same inthe plane x fr, Figjl.

Similar letters indicate corresponding parts. This invention relates toa registering-gauge the maximum hand of which is arrested immediatelythe main hand of the gauge falls back lby means of a lever-cam, whichbears on the circumference of a pl ane disk mounted on the hollow arboror hub of the maximum hand in such a manner that said maximum hand hasno dead. motion, and thus indicates at all times the exact maximumpressure to which the steain has been allowed-to rise during a certaininterval. With the cam-lever that serves to arrest the Amaximum hand iscombined a releasing-tappet, which is operated by a key, to be insertedthrough a hole in the case, and. which bears against a stop actuated bythe main-A spring ofthe gauge in such a manner that when the maximumhand has been carried to a certain point on the dial-plate it cannot becaused to fall backwhile the main hand stands on zero, and that, in casethe boiler explodes Without destroying the -steamgauge, the maximum handwill show the amount of pressure which exists in the boiler at themoment of the explosion.

In the drawing, the letter A designates a steam-gauge, the operation ofwhich is based on the action of the steam on a curved tubular spring, B,or upon a spring of any desired shape `secured in the interior of thecase, and from the upper or outer plate o rises a tubular projection, d,forming the guide for the hollow arbor e, carrying the maximum hand D. Acoiled spring,f, which acts on the hollow arbor e, has a tendency tocarry the maximum hand back to zero, while another coiled spring, f',acts in a like manner on the arbor a of the' main index 0. In this mainindex is secured a pin, g, and as the main index advances this pin bearsagainst the edge of the maximum hand and carries the same forward; butwhen the main index recedes the maximum hand is intendedA to stop so asto indicate` the highest point reached by the main index. On the hollowarbor of the maximum hand is firmly mounted t a disk, h, which issubjected to the action of a lever-cam, i, the point of which is pressedup against the circumference of the disk by a spring, j, said pointbeing so situated in regard to the fulcrum of the lever-cam that thedisk can revolve freely in a forward direction, indicated by arrow l inFig. 1; but if an attempt 'is made to turn the disk back the point ofthe cam immediately catches against the edge of said disk and retains itfirmly in position. By these means the maximum hand is arrestedimmediately the main index begins to recede. No dead motion of saidmaximum hand takes place, and the exact maximum pressure indicated bythe gauge is recorded. For the purpose of releasing the maximum hand andallowing it to recede to the starting-point, or until it comes incontact with the pin of the main index, a key, K, is used, which isinserted through the side of the case, and acts on a tappet, 7c, securedto a rod, l, the upper end of which forms an incline, m, and is loadedby a weight, u, by means of which said rod is held in contact with oneend ofA a lever, o, that swings on a fulcrum-pin, p, and the other endof which bears against or isconnected with the spring B of the gauge,the two arms of said rlever being so balanced that the weight of the armbearing against the tappet-rod Z keeps the opposite end of the lever incontact with the spring B. As soon as this spring recedes by thepressure of the steam the long arm of the lever o slides down on theincline m of the tappet-rod and the weight a carries thetappet 7cinward. lhe lever ois so adj usted that when the spring B of the gaugeis not exposed to press'- ure the tappet 7c will be kept back beyond theend of the lever-cam i; and if the maximum hand has been arrested at,say, one hundred and twenty pounds2 pressure and the main index hasreceded to the starting-point, the maximum hand cannot be brought backto its starting-point by the action of the key or other means short ofopening the case of the gauge. For as long as the spring B is notexposed to pressure, the tappet 7c, on being carried down by the actionof the key K, clears the tail of the lever-cam i, and the maximumhand'is not released; but as soon as steam is raised in the boiler andpermitted to act on the spring B the loose end of said spring recedes,the lever o allows the tappet 7c to fall in over the tailend of thelever-cam, and if the key K is inserted and turned in the properdirection the maximum hand is released and permitted to ily back incontact with the carrying-pin of the main index.

It will be readily seen that the lever o and the incline of thetappet-rod l can be so adjusted that it requires a pressure of ten,twenty, or more pounds in order to bring the tappet in position tostrike the taileend of the lever-cam f on being depressed.

The object of this arrangement is to keep a record of the pressureexisting in a boiler at the moment it explodes, and to prevent theproprietor of the boiler or the fireman from disturbing this record. Forif a boiler explodes at a pressureof, say, one hundred and twentypounds, the maximum hand of the gauge (provided the gauge is notdestroyed) will retain its position, While the main index recedes to thestarting-point, and, since the maximum hand in my gauge cannot bereleased unless the spring B is exposed to a certain pressure, (Withoutbreaking the gauge open,) a true record will be kept ofthe pressureexisting in the boiler at the moment of the explosion.

It is obvious that this invention is applicable to steam-gauges of anydesired construction, the action of which depends upon the pressure ofsteam on a spring Without regard to the form of such spring.

I do not claim, broadly, a detent-pawl operating upon the periphery of adisk or wheel but What I claim as new, and desire to secure by LettersPatent, is

1. The levercam i and plane disk h, in cornbination With the arbor a,hollowr arbore, and

hands C D, all arranged and operating substantially as and for thepurpose set forth.

2. The combination of the tappetrod-l,-le

ver o, levercam i, and disk h-With each other and with the spring andmaximum handof as'team-gallge, substantially as and for the-pur pose setforth.

JOSEPH KAYSER-l Witnesses:

W. HAUFF, E. RKAsTENnUBER.

